Multi-omics informed mathematical model for meropenem and tobramycin against hypermutable Pseudomonas aeruginosa.

Hypermutable P. aeruginosa isolates frequently display resistance emergence during treatment. Mechanisms of such resistance emergence have not been explored using dynamic hollow-fiber studies and multi-omics-informed mathematical modeling.

Cholesterol-terminated cationic lipidated oligomers (CLOs) as a new class of antifungals.

Infections caused by fungal pathogens are a global health problem, and have created an urgent need for new antimicrobial strategies. This report details the synthesis of lipidated 2-vinyl-4,4-dimethyl-5-oxazolone (VDM) oligomers an optimized Cu(0)-mediated reversible-deactivation radical polymerization (RDRP) approach. Cholesterol-Br was used as an initiator to synthesize a library of oligo-VDM (degree of polymerisation = 5, 10, 15, 20, and 25), with an α-terminal cholesterol group.

Population Pharmacokinetics of Meropenem Across the Adult Lifespan.

Background And Objective: We conducted an opportunistic pharmacokinetic study to evaluate the population pharmacokinetics of meropenem, an antimicrobial commonly used to treat Gram-negative infections in adults of different ages, including older adults, and determined optimal dosing regimens.

Methods: A total of 99 patients were included. The population pharmacokinetic models used had two compartments: zero-order input and linear elimination.

Ceftolozane/tazobactam disrupts Pseudomonas aeruginosa biofilms under static and dynamic conditions.

Background: Pseudomonas aeruginosa biofilms limit the efficacy of currently available antibacterial therapies and pose significant clinical challenges. Pseudomonal biofilms are complicated further when other markers of persistence such as mucoid and hypermutable phenotypes are present. There is currently a paucity of data regarding the activity of the newer β-lactam/β-lactamase inhibitor combination ceftolozane/tazobactam against P.

Utilizing an Opportunistic Clinical Study and Population-Based Pharmacokinetic Models to Identify Rational Empiric Dosing Regimens for Piperacillin-Tazobactam in Critically Ill Patients.

Determining an effective dosing regimen for piperacillin-tazobactam in critically ill patients is challenging due to substantial pharmacokinetic variability caused by complex pathophysiological changes. To address this need, a prospective clinical study was conducted, which enrolled 112 critically ill patients and employed an opportunistic sampling strategy. Population modeling and simulation were performed to characterize the pharmacokinetics (PK) and probability of target attainment (PTA) of piperacillin-tazobactam under various dosing regimens.

Population Pharmacokinetic Modeling of Cefepime, Meropenem, and Piperacillin-Tazobactam in Patients With Cystic Fibrosis.

Background: Patients with cystic fibrosis (CF) experience recurrent bacterial pulmonary exacerbations. Management of these infections is increasingly challenging due to decreased antimicrobial susceptibility to β-lactam antibiotics. The pharmacokinetics (PK) of these agents are inadequately characterized in patients with CF.

The effects of single and multiple resistance mechanisms on bacterial response to meropenem.

Objectives: Meropenem is commonly used against Pseudomonas aeruginosa. Traditionally, the time unbound antibiotic concentration exceeds the MIC (fT) is used to select carbapenem regimens. We aimed to characterize the effects of different baseline resistance mechanisms on bacterial killing and resistance emergence; evaluate whether fT can predict these effects; and, develop a novel Quantitative and Systems Pharmacology (QSP) model to describe the effects of baseline resistance mechanisms on the time-course of bacterial response.

Providing insight into the mechanism of action of cationic lipidated oligomers using metabolomics.

The increasing resistance of clinically relevant microbes against current commercially available antimicrobials underpins the urgent need for alternative and novel treatment strategies. Cationic lipidated oligomers (CLOs) are innovative alternatives to antimicrobial peptides and have reported antimicrobial potential. An understanding of their antimicrobial mechanism of action is required to rationally design future treatment strategies for CLOs, either in monotherapy or synergistic combinations.

Synergistic effects of inhaled aztreonam plus tobramycin on hypermutable cystic fibrosis Pseudomonas aeruginosa isolates in a dynamic biofilm model evaluated by mechanism-based modelling and whole genome sequencing.

Objective: Hypermutable Pseudomonas aeruginosa strains are highly prevalent in chronic lung infections of patients with cystic fibrosis (CF). Acute exacerbations of these infections have limited treatment options. This study aimed to investigate inhaled aztreonam and tobramycin against clinical hypermutable P.

Impact of conjugation to different lipids on the lymphatic uptake and biodistribution of brush PEG polymers.

Delivery to peripheral lymphatics can be achieved following interstitial administration of nano-sized delivery systems (nanoparticles, liposomes, dendrimers etc) or molecules that hitchhike on endogenous nano-sized carriers (such as albumin). The published work concerning the hitchhiking approach has mostly focussed on the lymphatic uptake of vaccines conjugated directly to albumin binding moieties (ABMs such as lipids, Evans blue dye derivatives or peptides) and their subsequent trafficking into draining lymph nodes. The mechanisms underpinning access and transport of these constructs into lymph fluid, including potential interaction with other endogenous nanocarriers such as lipoproteins, have largely been ignored.

Identifying and mathematically modeling the time-course of extracellular metabolic markers associated with resistance to ceftolozane/tazobactam in .

Extracellular bacterial metabolites have potential as markers of bacterial growth and resistance emergence but have not been evaluated in dynamic studies. We investigated the dynamic metabolomic footprint of a multidrug-resistant hypermutable isolate exposed to ceftolozane/tazobactam as continuous infusion (4.5 g/day, 9 g/day) in a hollow-fiber infection model over 7-9 days in biological replicates ( = 5).

Comprehensive stability analysis of 13 β-lactams and β-lactamase inhibitors in media, and novel supplement dosing strategy to mitigate thermal drug degradation.

Non-clinical antibiotic development relies on susceptibility and infection model studies. Validating the achievement of the targeted drug concentrations is essential to avoid under-estimation of drug effects and over-estimation of resistance emergence. While certain β-lactams (e.

Functionalisation of brush polyethylene glycol polymers with specific lipids extends their elimination half-life through association with natural lipid trafficking pathways.

Polymeric prodrugs have been applied to control the delivery of various types of therapeutics. Similarly, conjugation of peptide therapeutics to lipids has been used to prolong systemic exposure. Here, we extend on these two approaches by conjugating brush polyethylene glycol (PEG) polymers with different lipid components including short-chain (1C2) or medium-chain (1C12) monoalkyl hydrocarbon tails, cholesterol (Cho), and diacylglycerols composed of two medium-chain (2C12) or long-chain (2C18) fatty acids.

PmxPred: A data-driven approach for the identification of active polymyxin analogues against gram-negative bacteria.

The multidrug-resistant Gram-negative bacteria has evolved into a worldwide threat to human health; over recent decades, polymyxins have re-emerged in clinical practice due to their high activity against multidrug-resistant bacteria. Nevertheless, the nephrotoxicity and neurotoxicity of polymyxins seriously hinder their practical use in the clinic. Based on the quantitative structure-activity relationship (QSAR), analogue design is an efficient strategy for discovering biologically active compounds with fewer adverse effects.

Distinguishing Inducible and Non-Inducible Resistance to Colistin in Pseudomonas aeruginosa by Quantitative and Systems Pharmacology Modeling at Low and Standard Inocula.

Colistin is a polymyxin and peptide antibiotic that can yield rapid bacterial killing, but also leads to resistance emergence. We aimed to develop a novel experimental and Quantitative and Systems Pharmacology approach to distinguish between inducible and non-inducible resistance. Viable count profiles for the total and less susceptible populations of Pseudomonas aeruginosa ATCC 27853 from static and dynamic in vitro infection models were simultaneously modeled.

Single-dose pharmacokinetics and lung function of nebulized niclosamide ethanolamine in sheep.

Purpose: Niclosamide is approved as an oral anthelminthic, but its low oral bioavailability hinders its medical use requiring high drug exposure outside the gastrointestinal tract. An optimized solution of niclosamide for nebulization and intranasal administration using the ethanolamine salt has been developed and tested in a Phase 1 trial. In this study we investigate the pulmonary exposure of niclosamide following administration via intravenous injection, oral administration or nebulization.

Construction of a Synthetic Colostrum Substitute and Its Protection of Intestinal Cells against Inflammation in an Model of Necrotizing Enterocolitis.

Colostrum provides bioactive components that are essential for the colonization of microbiota in the infant gut, while preventing infectious diseases such as necrotizing enterocolitis. As colostrum is not always available from the mother, particularly for premature infants, effective and safe substitutes are keenly sought after by neonatologists. The benefits of bioactive factors in colostrum are recognized; however, there have been no accounts of human colostrum being studied during digestion of the lipid components or their self-assembly in gastrointestinal environments.

Ceftolozane-Tazobactam against Pseudomonas aeruginosa Cystic Fibrosis Clinical Isolates in the Hollow-Fiber Infection Model: Challenges Imposed by Hypermutability and Heteroresistance.

Pseudomonas aeruginosa remains a challenge in chronic respiratory infections in cystic fibrosis (CF). Ceftolozane-tazobactam has not yet been evaluated against multidrug-resistant hypermutable P. aeruginosa isolates in the hollow-fiber infection model (HFIM).

Development of a sustained release implant of benzathine penicillin G for secondary prophylaxis of rheumatic heart disease.

Background: Regular intramuscular (i.m.) benzathine penicillin G (BPG) injections have been the cornerstone of rheumatic heart disease (RHD) secondary prophylaxis since the 1950s.

Ceftolozane/tazobactam plus tobramycin against free-floating and biofilm bacteria of hypermutable Pseudomonas aeruginosa epidemic strains: Resistance mechanisms and synergistic activity.

Objective: Acute exacerbations of biofilm-associated Pseudomonas aeruginosa infections in cystic fibrosis (CF) have limited treatment options. Ceftolozane/tazobactam (alone and with a second antibiotic) has not yet been investigated against hypermutable clinical P. aeruginosa isolates in biofilm growth.

Population pharmacokinetics and target attainment analyses to identify a rational empirical dosing strategy for cefepime in critically ill patients.

Objectives: We aimed to identify rational empirical dosing strategies for cefepime treatment in critically ill patients by utilizing population pharmacokinetics and target attainment analysis.

Patients And Methods: A prospective and opportunistic pharmacokinetic (PK) study was conducted in 130 critically ill patients in two ICU sites. The plasma concentrations of cefepime were determined using a validated LC-MS/MS method.

Clinical pharmacological considerations in an early intravenous to oral antibiotic switch: are barriers real or simply perceived?

Background: Traditionally, there has been a common belief that ongoing i.v. antibiotic therapy is superior to an early i.

Population Pharmacokinetics of Piperacillin/Tazobactam Across the Adult Lifespan.

Background And Objective: Piperacillin/tazobactam is one of the most frequently used antimicrobials in older adults. Using an opportunistic study design, we evaluated the pharmacokinetics of piperacillin/tazobactam as a probe drug to evaluate changes in antibacterial drug exposure and dosing requirements, including in older adults.

Methods: A total of 121 adult patients were included.

Evaluation of Empirical Dosing Regimens for Meropenem in Intensive Care Unit Patients Using Population Pharmacokinetic Modeling and Target Attainment Analysis.

In the present study, population pharmacokinetic (PK) analysis was performed based on meropenem data from a prospective study conducted in 114 critically ill patients with a wide range of renal functions and various disease conditions. The final model was a one-compartment model with linear elimination, with creatinine clearance and continuous renal replacement therapy affecting clearance, and total bodyweight impacting the volume of distribution. Our model is a valuable addition to the existing meropenem population PK models, and it could be particularly useful during implementation of a therapeutic drug monitoring program combined with Bayesian forecasting.